摘要:
Crude polyorganophosphazenes, produced by the nucleophilic cosubstitution of polydichlorophosphazenes and contained in a reaction medium which includes such polyorganophosphazenes, reaction solvent for the cosubstitution reaction, excess nucleophilic reagent and/or product of neutralization thereof, and, when present, any alkali metal salts of neutralization, are efficiently and facilely purified, in a single treatment zone, advantageously under agitation in a discontinuous malaxator, by both eliminating the reaction solvent and thereafter washing the resulting reaction medium with a liquid which is a nonsolvent for the polyorganophosphazenes, but miscible with the other products present in said reaction medium.
摘要:
Essentially pure and colorless N-(dichlorophosphoryl)trichlorophosphazene [P.sub.2 NOCl.sub.5 ] is prepared/purified under relatively moderate conditions, by reacting phosphorous pentachloride with ammonium chloride, treating the resulting medium of reaction, containing P.sub.3 NCl.sub.12, with SO.sub.2, and thin film evaporating the medium of reaction, advantageously in two stages, to eliminate SO.sub.2, POCl.sub.3 and SOCl.sub.2 values therefrom.
摘要:
The sodium fluoroalcoholates are prepared under conditions resulting in neither reactant nor final product degradation, by (a) reacting, under reflux, the corresponding fluoroalcohols, e.g., the mono-, di- or trifluoroethanols, with sodium methanolate in the presence of a solvent having a boiling point higher than that of methanol and/or a solvent which forms an azeotrope with methanol, and (b) selectively trapping the methanol of reaction, e.g., in a molecular sieve, as it is released into the vapors which evolve upon refluxing the step (a) reaction mixture; the sodium fluoroalcoholates thus produced are well suited for direct reaction with polydichlorophosphazenes.
摘要:
A process for preparing linear polychlorophosphazenes having a terminal --PXCl.sub.2 group, wherein X is O or S, by polycondensation of a monomer of the formula P.sub.2 NXCl.sub.5, by heating to release PXCl.sub.3 and continuing the heating after the evolution of PXCl.sub.3 has stopped. In the process, at least the heat induced polycondensation phase after evolution of PXCl.sub.3 has stopped is carried out in solution in a medium which is a solvent for both the monomer and the polymer and which is inert to the constituents of the polycondensation reaction. The process reduces the amount of cross-linking and produces high molecular weight polymers in a reproducible way.
摘要:
The molecular weights of the poly(dichlorophosphazenes), and of the poly(organophosphazenes) produced therefrom, are controlledly regulated by heating such poly(dichlorophosphazenes) in the presence of an effective molecular weight-regulating amount of phosphorus oxychloride.
摘要:
The polycondensation disrupting effects of the impurities in an impure N-dichlorophosphoryltrichlorophosphazene, P.sub.2 NOCl.sub.5, or oligomer thereof, are avoided by polycondensing such impure P.sub.2 NOCl.sub.5 into a high molecular weight uncrosslinked poly(dichlorophosphazene) in the presence of an effective impurity-inhibiting, polymerization-controlling amount of phosphorous pentachloride, PCl.sub.5.
摘要:
Linear polychlorophosphazenes are more rapidly produced by polycondensing N-(dichlorophosphoryl)trichlorophosphazene [P.sub.2 NOCl.sub.5 ] in the presence of a catalytically effective amount of the bis(dichlorophosphoryl)imide of the formula: ##STR1##